Technical Field
The present invention relates to the technical field of devices for automatically inflating/deflating a capacity, e.g., a pneumatic tire of a vehicle wheel, using a gaseous fluid under relative pressure.
It is sometimes useful to be able to inflate or deflate the tires of the wheels of a vehicle remotely, so as to adapt the footprints and bearing capacities of said tires as a function of the state of the terrain over which the vehicle is moving.
This applies in particular to all-terrain vehicles that must be capable of making progress under the best possible conditions, equally well when travelling over hard, stony, and soft terrain in succession, without the driver being forced to interrupt the progress to make an appropriate correction to the inflation pressures of the various tires manually and while the vehicle is at a standstill.
This application is given merely by way of example because, in many fields, it is also useful or even necessary to be able to adapt remotely the inflation pressure of any confinement capacity for confining a gaseous fluid under relative pressure.
Description of the Related Art
To solve the above problem, it is known from the state of the art that it is possible to use a device 1 for automatically inflating/deflating a capacity. With reference to FIGS. 1 and 2 that show such a device 1 in longitudinal section, such a device comprises:
a first portion 2 including a control system 3 mounted to slide in a first chamber 4 under the effect of injection of a gaseous fluid via an intake orifice 5; and
a second portion 6, coupled to the first portion 2, and defining a second chamber 7 with an inflation/deflation orifice 8 designed to communicate with the confinement capacity (not shown), and a discharge orifice 9 opening out between said first and second portions 2, 6, said second portion 6 including a valve member 10 secured to the control system 3 in such a manner that it takes up a rest position in which it closes off the discharge orifice 9 and, when the control system 3 slides, it takes up a deflation position opposing a resilient return member 11 and in which it opens the discharge orifice 9.
When a gaseous fluid is injected into it, that device causes the control system to slide and thus causes the valve member to open the discharge orifice so as to deflate the confinement capacity.
That device may, for example, be mounted on all-terrain vehicles, which travel through puddles, dust, and/or mud. Sprayed dust, mud, and water can penetrate into the inflation/deflation device and damage it.
To mitigate that drawback, it is known from the state of the art that a protective washer 12 may be incorporated. That washer 12, which is preferably made of an elastomer material, is mounted between the first and second portions 2, 6 and around the discharge orifice 9 so as to protect it against external atmospheric agents, such as mud, water, and dust, or any other undesirable element that can be detrimental to operation of the device.
More precisely, that washer 12 is of frustoconical shape, the small base 12a of which shape, namely the inner perimeter of the washer 12 bears in sealed manner against the first portion 2, and its large base 12b, namely the outer perimeter of the washer 12 bears in sealed manner against the second portion 6.
That washer 12 makes it possible to maintain the device 1 sealed and to procure optimum protection from sprays and splashes of mud, water, dust, or any other element.
However, that solution for providing the sealing suffers from a major drawback. While the confinement capacity is being deflated, i.e., while gaseous fluid, in particular air, is being expelled from the device, and is being discharged via the discharge orifice, the washer made of an elastomer material is folded back to allow the air to discharge between said washer and the second portion. In other words, the large base of the frustoconical shape is pushed back towards its small base. Since the large base no longer in bearing contact, it finds itself in empty space. As a function of the pressure of the gaseous fluid that is released, the washer made of an elastomer material starts vibrating, thereby generating non-negligible undesired noise.
Such noise can be relatively problematic in certain fields, in particular when the device equips vehicles that are required to have a certain amount of stealth, e.g., military vehicles.